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Tidal lagoons offer enormous benefits to UK economy, study finds

By James Noble

July 24, 2014

Six tidal lagoons could contribute as much as £27billion over a 12-year period to the United Kingdom’s economy, a new study has found.

The study, titled “The Economic Case for a Tidal Lagoon Industry in the UK,” claims that the operation of the lagoons and the energy they produce could contribute £3.1 billion every year by providing thousands of jobs during construction and maintenance of the lagoons, while also supplying eight percent of the UK’s electricity.

Tidal lagoons are man-made enclosures, similar in appearance to harbours or marinas. Breakwater walls trap a body of seawater and separate it from the natural ebb and flow of the tides. Once the difference between the water levels inside and outside the lagoon is sufficient, sluice gates open, allowing the water to rush through the gaps and turn large turbines in the process. While tidal lagoons are based on proven technologies, none have been built yet.

To date, the scheme has gained high levels of public support and green groups see lagoons as less environmentally damaging because they are smaller and have a relatively insignificant impact on the tidal flow of an estuary, as a lagoon does not require blocking a river or a bay.

The prospect of a reliable, dependable renewable energy source reducing greenhouse gas emissions, providing economic development, and receiving support from environmentalists may sound promising to many.

But, there is one potential roadblock – the proposal is expensive. The Swansea Bay project is expected to cost £750 to £850 million to construct. Nevertheless, despite the high cost, the project has an expected lifetime of over a century and electricity production will be predictable and sustainable.

The UK’s six planned lagoons would be spread between the Severn Estuary, North Wales and the North West coast of England, with the first due to begin construction next Spring in Swansea Bay.